A form of puzzle which has been popular for many years has a series of rectangular blocks mounted on a common surface and generally residing in a common plane adjacent and parallel to that of the surface. The blocks are interlocked with each other and with a frame so that the blocks may be moved in the plane adjacent the common surface, but not removed from the frame. The blocks are configured so as to permit movement in two directions perpendicular to each other and parallel to the plane of the common surface, but not otherwise. The visible surface of the blocks have a series of numerals or an overall picture arranged so that when the blocks are in proper orientation, a meaningful pattern can be seen and when the blocks are disoriented, the pattern is jumbled.
A sliding block puzzle of the type described above is the subject of U.S. Pat. No. 1,101,567 for "Puzzle" to C. L. Ridgway. The puzzle of the '567 patent has numbers from 1-15 on each block and the blocks may be arranged in different sequences to vary the challenge.
In recent years, it has become common for places of public amusement, especially amusement places for children, such as, for example, fast food restaurants, to have large play devices for the clientelle to use. Up to now these devices have been mainly climbing and riding equipment. If a sliding block puzzle were made in a large size, it would be a positive addition to the equipment of such a play area. However, it is recognized that a puzzle such as that described would be best used in a vertical orientation, since a large play puzzle in a horizontal plane would require a lot of room and would be subject to being damaged if young players were to ride or stand on the pieces. A drawback to using this type puzzle in a vertical orientation however is that since it is necessary to retain one block space empty in order to permit the pieces to be moved, a block above an empty space would tend to fall down into that space.
The present invention makes it possible for the type of puzzle described above, previously useable only in a substantially horizontal orientation (large or small) to be used while mounted on a vertical surface, such as a wall or post.
Therefore, it is an objective of the invention to provide a sliding block puzzle that can be used while in a vertical plane.
It is a further objective of the invention to provide a sliding block puzzle constructed such that, when used in a vertical plane, the block directly above an empty space is prevented from falling.
It is an additional objective of the present invention to permit the blocks associated with a sliding block puzzle to be moved freely from position to position when so moved by a user.
These and other objectives will become apparent as the description of the preferred embodiment is disclosed below.